Optical reflector, an optical demultiplexer and an optical system

While relaxing the stringency of the arrangement of the optical filter, optical reflector capable of improving the performance of the wavelength-division multiplexing, to provide an optical demultiplexer and an optical system. Light reflector according to the present invention, the first optical fiber (14) and a second optical fiber connected regions to produce an intensity distribution of light corresponding to the wavelength of light, for example, a rod lens (12), on one side of the and (16), a mirror (18) provided on the other side, and an optical filter (20) provided between the first and second optical fibers and (14, 16) and the mirror (18) Yes doing. Optical filter (20) reflects light of a first wavelength, and transmits light of a second wavelength, the mirror (18) reflects the light of the second wavelength. Thus, between the first and second optical fibers (14, 16), the light of the two wavelengths are propagated.